4WD options-confused!

[lookn4runr]

Being in the market for a used 4Runner, I have encountered a few apparently different 4WD configurations, and am confused about the differences.

What I think I know:
1: Basic config. No rear LSD or Lock.
2: On Limited, Rear Lock, (is this true LOCK or LSD)?
3: On a 2001 I am looking at has, according to the window sticker (in glove box) "RR Diff", also has a switch on dash, looks like it lock/unlocks center diff.
I have had other trucks w/ 4WD, always w/ rear LSD. Any clarification welcome!
Thanks to all!

Bob

 

[RunnerUp]

alright, as far as the basic 4wd options for a 3rd gen, i think was only available on the 96-98 models, after that, 4wd models were equipped with a "new" 4wd, which allowed 4wd to be operated in the rain (i.e. selectable center locker, allowing wheels to break free on asphalt if not selected) the rear locker stopped in 01 i believe, and was replaced with ATRAC, which is basically a LSD in the front and the rear, works well for some terrain, but is no substiture for a locked diff.

if you see a RR lock button, it is TRUE lock, same for the center lock button, you are locked in....

 

[RonMAIDEN]

Rear diff and center diff locks are not the same and the rear diff along with the 5 speeds were discontinued after the '00 model year.
Limited's ('99+) were equipped with a multi mode auto which had the AWD mode and the center diff lock and some also had the rear diff lock.

Rear diffs lock the rear wheels positively together and will not slip period. Center diffs create a 50/50 torque split of the 4wd but will still allow slippage so you don't break anything. I think with the center diff lock off you get a bias toward the rear in 4wd.